Quantifying the role of thermal motion in free-space light-atom interaction

TL;DR

This paper investigates how the thermal motion of a single atom affects its interaction with free-space light, demonstrating measurable extinction and analyzing the impact of temperature on interaction strength.

Contribution

It provides experimental quantification of thermal motion effects on light-atom interactions and compares results with a simple theoretical model.

Findings

17.7% extinction of a weak coherent field by a single atom

Resonance frequency shift due to atomic heating

Initial temperature reduces interaction strength by less than 10%

Abstract

We demonstrate 17.7(1)% extinction of a weak coherent field by a single atom. We observe a shift of the resonance frequency and a decrease in interaction strength with the external field when the atom, initially at 21(1) $\mu$K, is heated by the recoil of the scattered photons. Comparing to a simple model, we conclude that the initial temperature reduces the interaction strength by less than 10%.